Photochemical stability of nonlinear optical chromophores in polymeric and crystalline materials

Abstract

We compare the photochemical stability of the nonlinear optical chromophore configurationally locked polyene 2-{3-[2-(4-dimethylaminophenyl)vinyl]-5,5-dimethylcyclohex-2-enylidene} malononitrile (DAT2) embedded in a polymeric matrix and in a single-crystalline configuration. The results show that, under resonant light excitations, the polymeric compound degrades through an indirect process, while the DAT2 crystal follows a slow direct process. We show that chromophores in a crystalline environment exhibit three orders of magnitude better photostability as compared to guest-host polymer composites.

Organic Phenolic Configurationally Locked Polyene Single Crystals for Electro‐optic and Terahertz Wave Applications

“…[15] The larger transparency range in the visible and the lower cut-off wavelength of OH1 crystals can be used for applications in the red and near-IR wavelength range and may also lead to a better photostability. [18] …”

Photostability enhancement studies on zwitterionic chromophores for nonlinear optics

“…[8][9][10][11][12][13][14][15][16][17][18][19] The main route for oxygen mediated photodegradation is via the generation of singlet oxygen, 1 O 2 , after the chromophore is optically excited from the singlet ground state, S 0 , to the singlet excited state, S 1 . 27,28 The relevant processes include S 1 + 3 O 2 →T 1 + 1 O 2 and T 1 + 3 O 2 →S 0 + 1 O 2 , where T 1 represents the triplet electronic state.…”

Molecular Structures and Second-Order Nonlinear Optical Properties of Ionic Organic Crystal Materials

“…Inside D-π-A conjugated organic ionic species, the cation is the main source of nonlinear properties, whereas the counter-anion is used to adjust the crystal packing through coulombic interactions [14][15][16][17]. The suitable combination of cation and counter-anion would lead to high second-order optical nonlinearity.…”